This application relates generally to communication systems, and, more particularly, to wireless communication systems.
Conventional wireless communication systems provide wireless connectivity to user equipment using devices such as base stations, access points, e-nodeBs, and the like. The base stations are typically connected to one or more antennas for transmitting and receiving radiofrequency signals. For example, some conventional wireless communication systems deploy antenna arrays that include arrays of antenna elements for transmitting and receiving signals. The passive antenna arrays used for uplink and downlink transmissions in legacy wireless communication systems can include multiple dipoles or other antenna elements that are driven by a single transceiver. Radiation from the multiple elements in a passive antenna array is therefore fully correlated.
Wireless communication equipment is designed to satisfy various requirements. One exemplary requirement includes an upper limit on the adjacent channel leakage ratio (ACLR) that is set by the requirement that leakage from one wireless communication channel should not reduce the capacity or throughput on another wireless communication channel by more than 5%. Compliance testing of equipment may be performed before the equipment is sold or deployed in the field to ensure that the wireless communication equipment satisfies the requirements. Equipment vendors and service providers may use the results of compliance testing to compare, select, purchase, configure, or deploy wireless communication equipment in the field. Compliance testing of passive antenna arrays can be performed by determining whether the test requirements are met at a reference point, such as a reference point at an antenna connection point or using far-field measurements at a distant reference point. For example, compliance testing at the antenna connection or in the far-field may be used to determine whether the transmitter satisfies a 45 dBc limit on the ACLR. The same requirements, such as the ACLR, can be applied at either the antenna connection point or the far-field point.